Exhibit 5.1

David G. Peinsipp

T: +1 415 693 2177

dpeinsipp@cooley.com

December 1, 2014

Ladies and Gentlemen:

You have requested our opinion with respect to certain matters in connection with the filing by New Relic, Inc., a Delaware corporation (the “Company”), of a Registration Statement (No. 333-200078) on Form S-1 (the “Registration Statement”) with the Securities and Exchange Commission, including a related prospectus filed with the Registration Statement (the “Prospectus”), covering an underwritten public offering (the “Offering”) of up to 5,750,000 shares of the Company’s Common Stock, par value $0.001 per share (the “Shares”).

In connection with this opinion, we have (i) examined and relied upon (a) the Registration Statement and related Prospectus, (b) the Company’s Amended and Restated Certificate of Incorporation and Bylaws, as currently in effect as of the date hereof, (c) the Company’s Amended and Restated Certificate of Incorporation, filed as Exhibit 3.2 to the Registration Statement (the “Post-IPO Certificate”), and the Company’s Amended and Restated Bylaws, filed as Exhibit 3.4 to the Registration Statement each of which is to be in effect immediately prior to closing of the Offering and sale and issuance of the Shares, and (d) the originals or copies certified to our satisfaction of such records, documents, certificates, memoranda and other instruments as in our judgment are necessary or appropriate to enable us to render the opinion expressed below and (ii) assumed that the sale and issuance of the Shares and the price at which they are issued will be authorized by the Pricing Committee of the Board of Directors and that the Post-IPO Certificate is in effect prior to the closing of the sale and issuance of the Shares. We have assumed the genuineness and authenticity of all documents submitted to us as originals, and the conformity to originals of all documents submitted to us as copies. As to certain factual matters, we have relied upon a certificate of an officer of the Company and have not sought independently to verify such matters. Our opinion is expressed only with respect to the General Corporation Law of the State of Delaware.

On the basis of the foregoing, and in reliance thereon, we are of the opinion that the Shares, when sold and issued as described in the Registration Statement and the related Prospectus, will be validly issued, fully paid and non-assessable.

We consent to the reference to our firm under the caption “Legal Matters” in the Prospectus included in the Registration Statement and to the filing of this opinion as an exhibit to the Registration Statement.

Sincerely,

/s/ David G. Peinsipp

David G. Peinsipp

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